Steel usually is manufactured in long slabs commonly called parent slabs. Due to their lengths, these parent slabs are very difficult to handle and transport, and, in order to make the steel available for use or for further processing in a plate mill, the parent slabs must be cut into shorter, more easily transportable slabs. The most commonly used method of cutting the parent slabs involves the use of a flaming torch. This method, which is called torch cutting, is very effective, except that it leaves residue on the steel where the cut was made in the form of torch dross or slab burr. This residue is an imperfection that must be removed prior to using the steel slabs or running them through a plate mill.
Accordingly, various methods and devices have been developed for removing this residue. A well known device is a hydraulically-operated assembly comprising a table, a knife and a rotatable pinch roll. The table comprises a plurality of axially-spaced rolls. The pinch roll is generally cylindrical and extends along the width of the table. The slab of steel is positioned on the table above the knife assembly, and is held in position by the pinch roller, which rests on top of the slab. The pinch roll and the table rolls are then rotated by a driving mechanism, causing the slab to traverse along the table, until the end of the slab passes over the knife shearing off the dross. The direction of rotation of the pinch roll and table rolls is then reversed so that the dross on the opposite end of the slab can be deburred. The cutting action effected by this device is not always effective, especially where the dross is heavy, because the lateral force applied by the pinch roll and table rolls is not always sufficient.
The knife used with this well known device comprises two single edges that face opposite directions along the table. Each edge is usually oriented at an angle relative to the direction of travel of the slab and being approximately in the same plane as the table. This orientation allows the knife to make what is called a progressive cut.
Accordingly, it is an object of this invention to provide a device and process for deburring steel that improves upon the prior art.
It is a further object of this invention to provide such a device and process that can deburr opposite edges of steel slab more effectively through the use of a pair of arms which are adapted to function not only as pinch rolls but also as pusher arms.
It is a still further object of this invention to provide a shearing knife assembly that improves upon the shearing knife heretofore known.